Well on my less than beer budget (I'm cheap) The static 32k byte devices I've pulled off of old 386 and 486 board are 25ns and below. Now he typical 30pin simms are 70ns dynamic rams. The core for PDP-8e generation was the limiting factor at 1.5uS or more than 20 times slower. The FPGAs I was playing with are as fast as late 70s TTL so there is no reason I cant do a faster PDP-8 with "old stuff". Then again the PDP-8e was limited by the 1970s tech of core speed not logic speed it could esily go faster if core could keep up. The mid 80s 6120 (Decmate II and III) CMOS pdp8 chip was faster too despite being microprogramed and multiplxed bus. However if your assumption that FPGA is one speed generation behind current silicon that makes it still under 1ns/cell which is plenty fast. Granted there is some speed penelty for nonoptimum routing. People that have done PDP-8s in FPGAs easily exceed the basic 8e speeds save for they don't seem to push them at all. As to the 1982 XT, that was slow by then standards by a factor of not less than 2. In 1982 the 8086/88 was up to 10mhz already. Allison